1. Field of the Invention
This invention is directed to herbicidal methods using quinoxalinyloxyphenoxyalkyl nitrile compounds which exhibit unexpectedly desirable selective herbicidal activity with high gramineous selectivity, while being relatively innocuous to corn.
Weed control is essential in the cultivation of important agronomic species such as corn, peanuts and cotton, as well as in the cultivation of many horticultural species. Moreover, the presence of such weeds on noncropped areas may present a fire hazard, or may result in the undesirable drifting of sand or snow or irritation to persons with allergies. Accordingly, control of weeds would be beneficial, particularly in a manner which would allow for the selective control of such plants without concurrent injury to desirable crops such as corn.
2. Description of Related Art
European patent application no. 42,750 is directed to certain quinoxaline compounds disclosed as being "particularly useful for selectively removing and controlling grass weeds, including volunteer corn" (page 85, lines 12-14; emphasis added). In contrast, applicants have found that certain quinoxalinyloxyphenoxyalkyl nitrile compounds exhibit herbicidal activity against grass weeds except corn, a desirable crop.
Chemical Abstracts 96:6755d (1982) relates to certain herbicidal quinoxalines which are said to cause no damage to cotton or soybean at 5-10 kg/ha by foliar application.
E.P. 46,467 is directed to certain quinoxaline derivatives which are said to give greater than 90% control of barnyard grass when applied pre-emergently at 25 grams per acre. European patent application no. 23,785 is directed to various quinoxalines which are said to be selective herbicides against monocotyledonous plants.